Long-used, little-studied laxative safe, effective

NEW YORK (Reuters Health) - Until now, a scant number of top notch clinical trials have evaluated whether sodium picosulfate -- the active ingredient in numerous over-the-counter laxatives -- is safe and effective.

Dr. Stefan Mueller-Lissner, at Charite-Universitatsmedizin Berlin, in Germany, and colleagues conducted such a trial and found sodium picosulfate both safe and effective for chronic constipation.

Sodium picosulfate, found in laxative pills and also in oral drinks that purge intestines and bowels in preparation for a colonoscopy exam, was identified as a laxative long before drugs had to be studied to become licensed, Mueller-Lissner explained in an email to Reuters Health.

Hence, sodium picosulfate lacks "a nice portfolio of controlled clinical trials" for researchers to compare with those of newer laxatives.

Mueller-Lissner's team began to address this oversight by testing sodium picosulfate versus a similar-tasting and looking inactive placebo in adults who had constipation for 13 years on average.

For 4 weeks, 233 participants took 18 sodium picosulfate drops (about 10 milligrams) by mouth each evening while the remaining 134 took 18 drops of the placebo. None knew which liquid they were taking, the researchers note in the American Journal of Gastroenterology.

Anyone with excessive diarrhea or severe abdominal discomfort, which can happen with laxatives, could cut their dose in half after consulting with a study investigator. Half of those taking the sodium picosulfate-containing laxative, but none taking placebo, did cut their dose by the end of the 4 weeks. The researchers provided laxative suppositories for use by anyone without a bowel movement for more than 72 hours.

The researchers report that far fewer people taking sodium picosulfate than the inactive placebo needed a suppository to have a bowel movement (21 percent versus 44 percent).

Moreover, the active laxative users reported better quality of life and were about twice as likely to rate their treatment favorably, even though they more often reported diarrhea and abdominal discomfort.

This study, the researchers say, offers evidence that over-the-counter laxatives containing sodium picosulfate are safe and effective. But Mueller-Lissner cautions anyone with unexplained constipation or bloody stools accompanied by a distended abdomen to seek medical advice.

SOURCE: American Journal of Gastroenterology, published online February 23, 2010